Adjustable headrest assembly for a dental chair

ABSTRACT

THE HEADREST ASSEMBLY HAS A HEAD RECEIVING DEPRESSION IN THE FRONT SURFACE THEREOF FOR HOLDING THE HEAD IN A CONFORTABLE, YET SECURE POSITION AT ALL TIMES. TO PERMIT CONVENIENT ACCESS TO ALL TOOTH SURFACES TO BE WORKED ON THE HEADREST ASSEMBLY IS SWIVELLY MOUNTED ON THE BACKREST OF A DENTAL CHAIN FOR ADJUSTABLE MOVEMENTS LATERALLY AND TRANSVERSELY OF THE BACKREST AND FOR ROTATIONAL MOVEMENT ABOUT AN UPRIGHT AXIS. A SINGLE CONVENIENTLY LOCATED LEVER IS READILY ACTUATED TO RELEASE THE HEADREST FROM AND TO LOCK THE HEADREST IN AN ADJUSTABLE MOVED POSITION.

G. A. FORTNAM March 6, 1973 ADJUSTABLE HEADRES'I ASSEMBLY FOR A DlNTAL. CHAIR iFiled uw 12, 1971 2 Sheets-Sheet. l

March 6, 1973 G. A. FORTNAM 3,719,388

ADJUSTABLE HEADREST ASSEMBLY FOR A DENTAL CHAIR Filed May l2, 1971 2 Sheets-Sheet 2 l amm A. llllll y mumllnnl Z "i, E; /0 Ffyrf/ j@ /2 5V WMM United States Patent O 3,719,388 ADJUSTABLE HEADREST ASSEMBLY FOR A DENTAL CHAIR George A. Fortnam, Des Moines, Iowa, assgnor to Den-Tal-Ez Mfg. Co. Filed May 12, 1971, Ser. No. 142,489 Int. Cl. A47c 7/38 U.S. Cl. 297-405 2 Claims ABSTRACT OF THE DISCLOSURE The headrest assembly has a head receiving depression in the front surface thereof for holding the head in a comfortable, yet secure position at all times. To permit convenient access to all tooth surfaces to be worked on the headrest assembly is swivelly mounted on the backrest of a dental chair for adjustable movements laterally and transversely of the backrest and for rotational movement about an upright axis. A single conveniently located lever is readily actuated to release the headrest from and to lock the headrest in an adjustably moved position.

SUMMARY OF THE INVENTION The headrest assembly is of a pleasing over-all appearance and easily manipulated to an adjusted position by a dentist without ypatient discomfort or annoyance. 'Ihe patients head is at all times received in a fully supported position in a head receiving pocket or cavity so that the patients head and the headrest are movable together to a desired adjusted or working position within a predetermined range of movements. The swivel support of the headrest on the chair backrest and its direct manipulation by the chair operator provides for adjustments being made quickly and easily with a minimum of interference with any dental work in process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a rear perspective view of a dental chair showing the headrest assembly of this invention in a position to be assembled therewith;

FIG. 2 is an enlarged rear elevational view of the headrest with parts broken away to more clearly show its construction;

FIG. 3 is a sectional view as seen on line 3-3 in FIG. 2;

FIG. 4 is an enlarged sectional detail view taken along line 4-4 in FIG. 2;

FIG. 5 is a sectional detail view of a swivel assembly as seen on line 5-5 in FIG. 4;

FIG. 6 is a perspective view of an adjustable member which forms part of the swivel assembly shown in FIG. 5;

FIG. 7 is illustrated similarly to FIG. 2 with parts shown in changed positions;

FIG. 8 is illustrated similar to FIG. 3 with parts shown in changed positions;

FIG. 9 is a sectional detail view taken on line 9 9 in FIG. 2; and

FIGS. lO, 1l and l2 are diagrammatic illustrations showing the adjustment of the headrest relative to a plurality of axes.

DETAIL DESCRIPTION OF THE INVENTION The headrest assembly of this invention, indicated generally as 15 in FIG. l, is intended for use with a dental chair 16 having a backrest 17 pivotally connected with a contoured seat and leg rest 18 which is mounted on a vertically adjustable floor supported base structure 19. The backrest 17 is movable to an adjusted position relative to the seat and leg rest 18 and the chair vertically moved on the base structure 19 by respective motor means (not shown) operable in a usual manner by control buttons 21 conveniently located on the backrest 17 for manipulation by a dentist or chair operator. The backrest 17 is formed with an upright cavity or socket 22 open to and located centrally of the top surface 23 of the backrest and of a size and shape to receive in a telescopic relation a depending tongue member 24 that comprises part of the headrest assembly 15. The tongue member 24 is longitudinally adjustable within the cavity 22 to provide for the vertical adjustment of the headrest assembly 15 relative to the backrest 17 to accommodate the height Of a patient seated within the chair 16. This adjustment is maintained by a locking screw 26 carried in the backrest 17 for movement into and out of locking or clamping engagement with the tongue member 24.

In its locked position with the backrest 17 the tongue member 24 functions as a mounting member for a swivel unit 28 which swivelly supports a headrest unit 27 (FIGS. 2 and 4) for pivotal movement laterally and transversely of the tongue member and for rotational movement about the axis of the swivel unit. The swivel unit 28 includes a ball member 29 that is integrally formed with an upwardly projected stem or shank member 31 and an associated socket means 32 comprised of a lower cup-shaped section 33 and an upright inverted cup-shaped section 34. The lower cup section 33 is positioned within a notch 30 in the top side of the tongue mem-ber and is rigidly secured to the tongue member as by weldments 35.

As shown in FIG. 4, the side wall 36 of the lower cup section 33 is externally threaded for threaded engagement with the internally threaded side wall 37 of the upper cup section 34. This threaded connection of the cup sections 33 and 34 is maintained by a locking or friction screw 38 threadable laterally through the side wall of the upper cup section 34 for engagement with the side wall of the lower cup section 33. The ball member 29 is received within the compartment formed by the cup sections 33 and 34 with the stem 31 thereof extended through an enlarged central opening 39 formed in the base wall 41 of the uppercup section 34. The opening 39 has a lirst side wall portion 42 of a shape corresponding to the curvature of the upper portion of the ball member 29 so as to form a stationary socket portion for the ball member. A second side wall portion 43 of the central opening 39 is sloped upwardly and outwardly in a concentrically spaced relation with the stem member 31 to provide for a tilting movement of the stern 31 within the opening 39.

Positioned within the lower cup section 33 (FIG. 5 for up and down movement axially thereof is a locking member 44 of a generally disc shape having an upper surface 45 of a size and shape for bearing engagement with the lower portion of the ball member 29. With the surface 45 of the locking member 44 in contact with, but out of locking engagement with the ball member 29, the ball member is freely and swivelly movable relative to the socket means 32 to a desired adjusted position of the head rest unit 27. With the headrest unit 27 in an adjusted position the ball member 29 is locked against movej 'i 3,719,388I

ment within the swivel means 32 by an upward movement of the locking member 44 to clamp the ball member between the surfaces 42 and 4S on the upper cup section 34 and locking member 44, respectively.

Movement of the locking member 44 into and out of locking engagement with the ball member 29 is accomplished by means including an elongated cam member 46 (FIGS. 4 and 5) extended diametrically through the side wall 36 of the lower cup section 33 with end p0rtionsthereof rotatablyl mounted in opposite portions of the cup side wall 36 and a cam section 47 located within the cup section 33 for bearing engagement against the under side of the locking member 44. On rotation of the cam member 46 in one direction the locking member 44 is engaged and moved by the cam section 47 into locking engagement with the ball member 29. On rotation of the cam member 46 in an opposite direction the locking member 44 is permitted to move out of locking engagement with the ball member 29.

This action of the locking member 44 into and out of "i locking engagement with the ball member 29 is initially set up and then maintained by the provision for relative axial movement of the cup sections 33 and 34. Thus' with the ball member 29 located within the cup sections and the cam section 47 in a ball release position relative to the locking member 44, the cup sections 33 and` 34 are threadably adjusted until the ball member 29 is snugly litted between the upper cup section 34 and the surface 45 of the locking member 44. This adjusted position of the cup sections 33 and 34 is rigidly'secured by the locking screws 38. On movement of the cam section 47 to a ball locking position, therefore, the ball member 29'is frictionally clamped between and in locking engagement with the surface 45 of the locking member 44, and the surface 42 of the upper cup section 34.

The headrest unit 27 includes a plate member 49 (FIGS. 2 and 3) having an integral lower enlarged section 51 formed with a downwardly facing hole 52 to receive the ball stem 31. The plate member 49 is secured to the stem 31 in a usual manner by a friction screw 53. A base or mounting member 54 of a .plastic composition for supporting a resilient contoured head member S6 is attached to the plate member by screws 57.

The head member 56 (FIGS. 3 and 4) has a rear surface of a shape for full mating engagement with the entire front surface of the base member 54. A covering material 55 such as a fabric reinforced vinyl is fitted over the head member S6 with the marginal portion thereof extended over a marginal rim 58 formed on the rear side of the base member 54. A rear cover plate 59 of a size and shape to lit over the marginal rim 58 is secured as by screws 61 to the base member 54. A housing portion 62 integrally formed with the rear cover plate 59 shields the swivel unit 28. The handle member 48 'is projected from one side of the housing portion 62 to provide for its manipulation by either the left or right hand of the chair operator. i ,Y

It is seen, therefore, that with the handle memberH 48 actuated to release the ball member 29 for a swivelmovement of the stem 31 that the head rest unit 27 is concurrently or separately movable relative to a plurality of axes having a common origin in the longitudinalvaxis of the tongue member 24. To limit the range of adjustable movement of the head rest unit 27 the upper end of the tongue member is provided with a pair of transversely opposite laterally extended lingers 63. Correspondingto the iingers 63 is a pair of cavities or recesses 64` formed in the base member 54 at opposite sides of the tongue member 24. yEach vcavity has an upper wall 66, allower wall 67, a front Wall 68 and an open rear side 69. A linger 63 extends horizontally within an adjacent cavity 64 at a position intermediate the upper andlowerwalls thereof and spaced from the front wall 68 when the headrest unit 27 is in a neutral position, namely, the ball l4 member stem 31 isrin coaxial alignment with the longitudinal axis of the tongue member 24.

-Pivotal or tilting movement of the headrest unit 27 in a direction transversely of the tongue member 24 is limited by the engagement of the ends of the lingers 63 with an upper or lower wall of a cavity 64 as shown in FIG. 7. In other words, on movement of a cavity wall 66 or 67 into engagement with a nger 63, the head rest unit has been transversely tilted to a maximum position as illustrated diagrammatically in FIG. 1l.

A rotational movement of the headrest unit 27 about the axis of the ball stem memberl (FIGS. 9 and 12) is limited by the engagement of one of the fingers 63 with the front wall 680i one of the cavities 64. The extent of this rotational movement of the headrest unit 27 is thus initially determined by the distance between a front wall 68 and its corresponding linger 63 when the headrest unit is in the neutral position therefor.

The tilting or pivotal movement of the headrest unit 27 laterally of the tongue member 24 is limited by the engagement of the ball stem member 31 with the side wall surface 43 of the central opening 39 (FIGS. 5, 8 and 10). Such engagement, to limit the fore and aft pivotal movement of the vheadrest unit 27, occurs at diametrically opposite portions of the side wall surface 43.

It is seen, therefore, that on the release of the ball member 29 out of locking engagement with the socket means 32 the headrest Aunit 27 is easily and quickly manually movable bythe chair operator to an adjusted position within dened limits. These defined limits pro- `for movement concurrently with the head rest unit 27 to an adjusted position.

In the vertical adjustment of the tongue member 24 relative to theV chair backrest 17, the headrest assembly 1S might be accidentally dropped prior to any manipulation of the locking screw 26. Should this occur, there is provided a rubber bumper 71 on the tongue member at a position spacedvv downwardly from thev lower cup section 33. -The engagement of the bumper 71 with the top surface 23 of the backrest 17 not only eliminates any possible damage to the headrestassembly but prevents the linger of an operator from being caught between the lower cup section 33 and the top surface of the backrest 17. f

Although the invention has been described with respect to'aY preferred 'embodiment thereof,"it is to beunderstood that it is not to be so limited since changes can be Imade therein which are within the full intended scopeof this invention as dened by theV depended clams.

I claim; j

1. An adjustable headrest assembly for a dental chair having a backrest with an upright hole open to the top surface of said backrest comprising: n

`(atan elongated support member receivable within l :said hole, 'j v b) asocket unit mounted on said support member, (c) a ball member swivelly supported within said socket unit having a radially extended stem member, (d) a headrest unit secured to said stem'` member for swivel movement with said ball member, (e) means on said socket unit for releasably locking said ball-'member against movement in a'swivelly v moved position, and (f) coacting means on said support member and said headres'tunitfor relatively limiting the swivel movement of said headrest unit in directions transversely and laterally of v,said support member, and rotatably about the axis of said stem member.

2. The headrest assembly according to claim 1 wherein:

(a) said coacting means includes a pair of transversely opposite outwardly projected stop ngers on said support member, and

(b) said head1-est unit includes a base member having 5 a pair of cavities corresponding to said pair of stop ngers positioned at opposite sides of said support member, each finger extended within a corresponding cavity and engageable with certain wall portions of an associated cavity in response to a swivel -rnovement of said headrest unit transversely of said support member or rotatably about the axis of said stern member.

6 References Cited UNITED STATES PATENTS 684,841 10/1901 Merkel' 297-405 3,574,398 4/1971 Hairgrove 297-410 1,008,456 11/1911 Etter 297-405 2,181,465 11/1939 Schneider 297--405 3,508,788 4/1970 Barton et al 297-410 O FRANCIS K. ZUGEL, Primary Examiner D. F. MARQUETTE, Assistant Examiner U.S. Cl. XR. 297-410 

